This research is concerned with oropharyngeal shedding of Epstein-Barr virus in various clinical disorders. Current studies are concerned with the frequency of pharyngeal excretion of EB virus in patients with Burkitt lymphoma, and other African tumors, in family members of the Burkitt lymphoma cases and in healthy African control subjects. In addition, the relationship of EB virus oropharyngeal excretion in infectious mononucleosis to functional capacities of cell mediated immunity and to continue EBV-specific IgM antibody production is being investigated.